The subject has been an issue in London where celebrities have boycotted the city's trendy Nobu restaurant for serving endangered bluefin tuna. And now the species has a royal champion.

Prince Alberthas persuaded all the restaurants and hotels in the principality of Monaco not to serve the fish.

"It cannot be business as usual with the bluefin tuna," insists the prince. "Stocks are being wiped out. What we have done in Monaco is stop demand at source."

His action comes after Elle Macpherson, Stephen Fry, Sting and Jemima Khan signed a letter demanding that the Michelin-starred Japanese fusion restaurant chain Nobu, which is part-owned by Robert De Niro, take the fish off the menu. In the document they said they can longer "dine with a clear conscience" at the eatery.

The sushi haunt had earlier added an asterisked note notifying customers the species is critically endangered to the bluefin entry, but declined to remove it altogether.

Nobu co-owner and head chef Nobu Matsuhisa is looking into replacing wild bluefin with a farmed version raised in Australia or Japan